Improvement in steam-engine slide-valves



NA PETERS, FHOTO-LITHOGRAPHER. wA SHxNaToN D C llutrd giant JOHN F. ALLEN, 0F TREMONT. NEW YORK.

Letters Patent No. 95,868, dated October 19, 1869.

IMPRDVEMENT IN STEAM-ENGINE SLIDE-VALVES.

The Schedule referred tb in these Letters Patent and making part of the same.

To all whom it may concern:

Be it known that I, JOHN F. ALLEN, of Tremont, iu the county of Westchester', and State ot' New York, have invented a new and improved Slirle-'valve and I do hereby declare that the following isa full, clear, and exact description thereof, .which will enable others skilled in the art to make and use the same, reference being had to the accompanying drawing, forming part of this specification, in which- Figure 1 represents a vertical longitudinal section of my improved slide-valve.

Figure 2 is a vertical transverse section of the same, taken on the plane ofthe line x, fig. 1.

Figure 3 is a horizontal section of the sanie, taken on the plane of the line y y, tig. 2.

Figure 4 is adetail longitudinal vertical section of a modification ofthe same.

Similar letters of reference indicate coiresponding parts.

This invention relates to a new equilibrium slidevalve, which is so arranged that it forms four openings for the steam inlet, those on top conducting the steam through the body ofthe valve.

The invention consists in the arrangement of a flat valve, which is verticall) perforated through the middle, and which rests on an elevated plane of the steamchest, and under a grooved or recessed cap, so as to admit steam at both ends, both from top `and bot-tom, that passing over the top going through the aperture of the valve into the steam-port.

The invention also consists in providing two transverse partitions across the aperture of the valve, to divide the same into three openings, those at the ends being connected with each other by open tubes that pass through the middle aperture.

This latter kind ot' valve is used over an inlet and exhaust-port at once, and operates in relation to two grooves, or recesses in the upper cap, as hereinafter more fully described.

A, in the drawing, represents a steam-cylinder, in which a a are the inlet-ports, and b b the exhaustports, leading to the e'exh:rust-channel c, the exhaustports being near the inlet-ports, as shown.

B is the steam-chest, receiving the steam through a suitable pipe, O.

D D are the two slide-valves, working above the inlet, and exhaust-ports at the ends of the cylinder, respectively.

They are securedto and connected by the valverod E.

That portion of the cylinder-top on which each silde-valve works is bevelled and somewhat raised above the other parts of the top, so as to form shoulders d'e, as shown. v

A cap F, is arranged in the steam-chest, above each valve, as longl as the planed surface of the cylinder-top between the lshoulders l c, as shown, and the upper face ofthe valve works nicely on the under side ofthe stationary cap.

This cap has two transverse recesses, or grooves, f and y, on its under side, between the three projecting libs, h', i, and 1.', as shown.

Each valve is made ot' rectangular form, and consists of two side' bars, l Z, that are connected by four transverse bars, on, a, o, a-nd p, forming three slots, or openings, q, fr, and s, between them.

The openings q and s are connected with each other by one or more open tubes, t t, that pass longitudinally through the cross-bars n o, and through the opening "r, as shown in fig. 3.

When the slide-valve is in position to admit steam to a port, its cross-bar m stands about midway across the broader port a, as ou the valve D, in tig. 1, while the cross-bar p projects beyond the shoulder c.

Steam can then, from the chest, pass directly into the port (t, as per arrow 1; also over the cross-bar fm', into the groove j, through the aperture q, into thel port a, as per arrow 2; also, from below, into the opening s, and through the tribes t, into the opening @and thence into the steam-port, as per arrow 3, as well as from above, into the same opening s, tubes t, opening q, and port a, as per arrow 4.

When the valve is in position for exhausting the steam, its bars, m and p, lit under the ribs h and It of the cap, as shown in the position of the valve D, in fig. 1.

The steam can then pass from the port ainto the opening fr, and down into the port b', as per arrow 5; or through the opening q, recess f, and opening fr, into the port b', as per arrow (i or through the opening q, tubes t, and opening s, into the port b', as per arrow 7 or through the opening o', recess g, and opening s, into the port b', as per arrow 8. Thus there are four inlet and four outlet-passages.

In either case, the steam can enter or exhaust through the body of the valve.

The motion ot' this valve can be very short, as it need only can-y the bar m from the middle of the port a to the outer end of the same.

1When the valve is used on an inlet-port alone, as in fig. 4, the cross-bars n and o and tubes t can be dispensed with, so that the valve will form a mere rect` angular open frame.

The cap F has, in this case, only one groove, or recess, r.

The steam can then enter the opening u of the valve either from under the bar 11, as per arrow 9, or over the same, as per arrow 10, or over the bar 1n. and through the groove t', as per arrow 11,or it may enter the port directly, as per arrow 12, in tig. 4.

I claim as new, and desire to secure "by Letters Patent- 1. A'peiforated slide-Valve, constructed as shown,

whereby to admit the steam by four courses, allowing it to pass through the body of the valve, substantially as herein shown and described.

2. A peiforated slide-valve, having the cross-bars a o and connecting tube or tubes t, to admit or exhaust the steam by four different passages, as specified.

3. The cap F, arranged in 95ste the steam-chest, above the perforated slide-valve, and provided with one or two grooves, or recesses, to admit the steam above the valve, substantially as herein Witnesses:

i FRANK BLooKLEY,

ALEX. F. ROBERTS. Y,

shown and described.

JOHN F. ALLEN. 

